Shots pulling fast on very fine grind (grinder problem?)

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jack556

#1: Post by jack556 »

Hi all,

I've been having an issue in recent months whereby I need to keep grinding finer and finer on my grinder to achieve proper extraction times. I am nearing the finest setting of my grinder (Eurek Mignon Manuale) and the shots were pulling very fast (10-15s), even with beans roasted 8-10 days prior.

I flagged this with the supplier of my Grinder and send them pics of my burrs and they advised new burrs (even though the grinder at the time was only a year old). I replaced the burrs a few weeks ago but I'm still having the same problem. Here's an example:

EXAMPLE OF PROBLEM:
I'm using a Lelit Anna PL41EM and grinding 18.5g (SquareMile Redbrick) into an Ascaso 57mm precision filter with a grind setting on the bottom end of the Grinder's adjustment (grinds feel like fine sand, one notch more and the burrs touch). This then pulls 42g of coffee in the cup in 15s-18s - the espresso instantly pours out of the portafilter at a very fast rate. Pressure only builds to around 8 bars also and then drops significantly.



There appears to be no channeling in the puck and I'm using a puck screen aswell just incase. I'm confident in my puck prep as this issue has only just started to happen in the last few months. Using the same beans and prep in the past, it would extract this same amount in around 28-32s, and this would be with the grinder adjusted around a whole notch coarser too!

I can only assume that there is an issue with grinder burrs alignment or something because everything I am doing in terms of dosing, brew temp, bean freshness etc. has all been the same, but I now need to grind a lot finer and it still extracts too fast. Changing the burrs doesn't seem to have changed much - could it be possible I am grinding too fine and the coffee just dissolves or Is this a silly suggestion lol? :roll:

Any suggestions/advice would be greatly appreciated.

Many thanks,
Jack

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Jeff
Team HB

#2: Post by Jeff »

If the "grinds feel like fine sand" at the finest setting before burr touch, it sounds to me like a grinder problem. Everyone's concept of fine is different, so this is only a guess. I would hope to be able to get to a finer texture, if not into a powdery texture, with a conventional grinder intended for espresso. (Some burr sets intended for brew might not get very fine.)

BaristaMcBob

#3: Post by BaristaMcBob »

The only way to rule out channeling is to use a bottomless portafilter.

What is the basket dose rating? How many grams are you dosing? If you put too much, you'll crush the puck when you latch in the portafilter, which will result in massive channeling. There should be at least 2mm clearance between the dry puck and the shower screen. Use a coin to check this. FWIW, I dose 17g in a 21g basket.

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cafeIKE
Supporter ❤

#4: Post by cafeIKE »

Jim Schulman posted on CoffeeGeek a lifetime ago.

Generally, a quick way to check grinds is to pinch them between your fingers and feel how granular they are:
  • Turkish:
    a powder, like flour.
  • Espresso:
    very fine grained, like 10x sugar
  • Drip (fine grind):
    like fine sand
  • Medium Grind (vacuum pots, fast French Press, and cupping):
    a tad finer than table salt
  • Coarse (for slow french press):
    between table and kosher salt.

Pressino

#5: Post by Pressino »

I agree with Jeff that it sounds like a grinder problem, and not a burr problem, as you've installed new ones (presumably designed for espresso). That leaves the grinder itself and most likely something off in the burr holding/grind adjustment mechanism. Could be as simple as a need to recalibrate the zero. Or as complicated to diagnose and fix as burr misalignment.

A good and fairly inexpensive way to determine whether your grinder is grinding fine and consistently enough is to run your grounds through a series of filters (like Kruve). These filter sets have other uses as well. They are not cheap, but I think their cost is justifiable for someone who is very serious about coffee.

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borrik

#6: Post by borrik »

My suggestion is to try other less sophisticated mid-dark roast beans.They should not be like sand, but sticky and clumpy and on minimum grind will choke your espresso machine.

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another_jim
Team HB

#7: Post by another_jim »

Dial the grinder down so you hear it very slightly chirp, and put a good load of (throwaway) beans in the hopper. The beans should grind to a powder (Turkish grind). If you feel granularity and the burrs chirp, you burrs are grossly misaligned. If the burrs do not accept beans, that is a good thing -- coarsen up the grind a little until it starts chewing the beans -- at that minimum setting, the grind should be a powder.
Jim Schulman

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BaristaBoy E61

#8: Post by BaristaBoy E61 »

You should be able to hear the burrs chirp as you approach zero.

Your next step would be to open up the grind chamber and do a removable felt pen marker test around the burr's outer perimeter to determine if they can touch and where.

Search for burr alignment & shimming threads on HB.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

jack556 (original poster)

#9: Post by jack556 (original poster) »

Thank you all for your replies and advice! I think I may have found what's contributing to the issue:

I tried taking the grind setting down to the chirp point (which I haven't done in a while but remember where it roughly was on the adjustment knob) and noticed that I need to go a whole step finer to get them to touch! Before I would need to go 1 or 2 steps below 0 on the adjustment knob to make them just touch and now its more like 3 stops finer.

So it's almost as if the reference on the adjustment knob has come out of sync with the factory reference - which is making it seems like I'm needing to grind finer but its just the adjustment knob and 'slipped' out of sync, is that possible on a stepless like the Mignon?

The grinds at the chirp point are a really fine 'baby powder' like texture so that's all okay. I think in my frustration, I hadn't properly examined the texture of my grinds as they've been coming out much coarser than usual. But I think it may have been a case of my adjustment dial reference is wrong rather than it's grinder coarser than it should!

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Kaffee Bitte

#10: Post by Kaffee Bitte »

Is the grinder newish? It almost sounds like you have just settled into a seasoned burr set. About 10 to 20 lbs of coffee through it?
Lynn G.
LMWDP # 110
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